A method for manufacturing a perpendicular magnetic recording transducer is described. A metallic underlayer, an insulator on the metallic underlayer, and a metal mask on the insulator are provided. The metal mask has an aperture therein. A trench is formed in the insulator. The trench's bottom is narrower than its top and includes part of the metallic underlayer. The top has a width of not more than 0.28 micron. A nonmagnetic seed layer that substantially covers at least the trench bottom and sides and that has a thickness of at least five hundred Angstroms is provided. A perpendicular magnetic pole material is plated on at least part of the seed layer. A cmp is performed, removing part of the perpendicular magnetic pole material. A remaining portion of the perpendicular magnetic pole material forms a perpendicular magnetic recording pole. The nonmagnetic seed layer is a stop layer for the cmp.
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8. A method for manufacturing a perpendicular magnetic recording transducer comprising:
providing a metallic underlayer, the metallic underlayer being conductive;
providing an insulator on the metallic underlayer;
providing a metal mask on the insulator, the metal mask having an aperture therein;
forming a trench in the insulator in a location corresponding to the aperture, the trench having a top, a bottom narrower than the top, and sides, the bottom of the trench including a portion of the metallic underlayer, the portion of the metallic underlayer being adjacent to an air-bearing surface and conductive;
providing a nonmagnetic seed layer, the nonmagnetic seed layer substantially covering at least the bottom and sides of the trench;
plating a perpendicular magnetic pole material on at least a portion of the seed layer; and
performing a chemical mechanical polish (cmp) to remove a portion of the perpendicular magnetic pole material, a remaining portion of the perpendicular magnetic pole material forming a perpendicular magnetic recording pole, the nonmagnetic seed layer being a stop layer for the cmp.
1. A method for manufacturing a perpendicular magnetic recording transducer comprising:
providing a metallic underlayer, the metallic underlayer being conductive;
providing an insulator on the metallic underlayer;
providing a metal mask on the insulator, the metal mask having an aperture therein;
forming a trench in the insulator in a location corresponding to the aperture, the trench having a top, a bottom narrower than the top, and sides, the bottom of the trench including a portion of the metallic underlayer, the portion of the metallic underlayer being adjacent to an air-bearing surface, the top of the trench having a width of not more than 0.28 micron;
providing a nonmagnetic seed layer, the nonmagnetic seed layer substantially covering at least the bottom and sides of the trench, the nonmagnetic seed layer having a thickness of at least five hundred Angstroms;
plating a perpendicular magnetic pole material on at least a portion of the seed layer; and
performing a chemical mechanical polish (cmp) to remove a portion of the perpendicular magnetic pole material, a remaining portion of the perpendicular magnetic pole material forming a perpendicular magnetic recording pole, the nonmagnetic seed layer being a stop layer for the cmp.
2. The method of
3. The method of
5. The method of
7. The method of
depositing a metal mask layer;
providing a photoresist mask having a pattern on the metal mask layer; and
transferring the pattern of the photoresist mask to the metal mask layer.
9. The method of
10. The method of
11. The method of
depositing a metal mask layer;
providing a photoresist mask having a pattern on the metal mask layer; and
transferring the pattern of the photoresist mask to the metal mask layer.
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The present invention is related to co-pending U.S. patent application Ser. No. 11/367,819 entitled “METHOD AND SYSTEM FOR PROVIDING PERPENDICULAR MAGENTIC RECORDING TRANSDUSCERS” (K35R 1969), filed on Mar. 3, 2006 and assigned to the assignee of the present application.
The present invention relates to magnetic recording technology, and more particularly to a method and system for providing perpendicular magnetic recording transducers.
The conventional PMR transducer 10 includes a conventional first pole 12, alumina insulating layer 14, alumina underlayer 16 that may be considered part of the alumina insulating layer 14, a conventional PMR pole 18 that typically includes a seed layer (not shown), insulating layer 20, shield gap 26, top shield 28, and insulating layer 30. Note that in certain other embodiments, the top shield 28 may also act as pole during writing using the conventional PMR transducer 10. The conventional PMR pole 18 and the top shield 80 are surrounded by insulating layers 20 and 30, respectively. The conventional PMR pole 18 has sidewalls 22 and 24.
In conventional applications, the height of the conventional PMR pole 18 is typically less than approximately three-tenths micrometer. The conventional PMR pole 18 also has a negative angle such that the top of the conventional PMR pole 18 is wider than the bottom of the conventional PMR pole 18. Stated differently, the angle θ of the sidewalls is less than ninety degrees in the conventional PMR pole 18 of
Although the conventional method 50 may be used to fabricate the conventional PMR pole 18, there are drawbacks. For example, the changes in the length of the RIE performed in step 54 results in varying thicknesses of the trench. Consequently, the height, h, of the conventional PMR pole 18 may vary. Such a variation between conventional PMR poles 18 is undesirable.
Accordingly, what is needed is an improved method for fabricating a PMR head.
A method and system for providing a perpendicular magnetic recording transducer are disclosed. The method and system comprise providing a metallic underlayer and providing an insulator, at least a portion of which is on the metallic underlayer. The method and system also comprise forming a trench in the insulator. The bottom of the trench is narrower than the top of the trench and includes a portion of the metallic underlayer. The method and system further comprise providing a nonmagnetic seed layer that substantially covers at least the bottom and sides of the trench. The method and system also comprise plating a perpendicular magnetic pole material on at least a portion of the seed layer and removing a portion of the perpendicular magnetic pole material. A remaining portion of the perpendicular magnetic pole material forms a perpendicular magnetic recording pole.
The present invention is related to co-pending U.S. patent application Ser. No. 11/367,819 entitled “METHOD AND SYSTEM FOR PROVIDING PERPENDICULAR MAGENTIC RECORDING TRANSDUSCERS” (K35R 1969), filed on Mar. 3, 2006 and assigned to the assignee of the present application. Applicant hereby incorporates by reference the above-identified co-pending patent application.
In the above-identified co-pending application, a method for forming a PMR transducer is described.
A trench is formed in the insulator under the aperture, via step 84. The metal mask thus acts as a mask for trench formation, exposing the portions of the insulator in which the trench is to be formed and covering adjacent regions. The trench has a top that is wider than the bottom. The bottom of the trench is on the magnetic seed layer. The top of the trench formed in step 84 may be less than or equal to 0.14 micron. The metal mask is removed, via step 86. In some embodiments, step 86 may be performed using a RIE process. A magnetic seed layer is deposited in the trench, via step 88. Examples of the magnetic seed layer include but are not limited to NiFe, CoNiFe, and CoFe. A pole material is plated in the seed layer, via step 90. Thus, the pole material is magnetic and may include multiple sub-layers. A planarization is performed, via step 92. Consequently, a portion of the magnetic pole material may be removed. The portion of the magnetic pole material remaining in the trench in combination with the magnetic seed layer may form a PMR pole. Processing of the PMR transducer may then be completed.
Thus, using the method 70, a PMR transducer analogous to conventional PMR transducer 10 may be provided. Because the metal layer provided in step 72 is the bottom of the trench, variations in the height of the PMR pole may be reduced. Although the method 70 functions well for its intended purpose, plating of the pole material in step 90 may be difficult for lower pole widths. In particular, assuming the pole width is measured at the top of the PMR pole, when the pole width is less than or equal to approximately 0.14 micron, plating of the pole material may be problematic. Using the method 70, the trench has the same shape and width as the PMR pole. It is believed that the seed layer provided in step 90 may be unable to adequately cover the side walls of the trench formed in step 84 when the pole width, and thus the trench width, are less than or equal to approximately 0.14 micron. As a result, the material(s) in the pole material may be unable to adequately adhere to the underlying insulator. Thus, the pole material is unable to remain in the trench and the yield for the method 70 may be low.
A metallic underlayer is formed, via step 102. The metallic may be formed on an underlying insulator. In such an embodiment, a shallow trench is may be formed in the insulating layer, and the metallic underlayer is formed in the trench. However, in another embodiment, the metallic underlayer may be part of another structure, such as a pole. The metallic underlayer may include nonmagnetic metallic materials. Examples of such materials include, but are not limited to Cr, NiCr, NiNb, Ru, and Ta.
An insulator is provided on at least part of the metallic underlayer, via step 104. In one embodiment, the insulator substantially covers all of the metallic underlayer. In another embodiment, the insulator may cover only a portion of the metallic underlayer. In a preferred embodiment, the insulator is alumna. The steps 102 and 104 are analogous to the method 70 depicted in
A nonmagnetic seed layer is provided, via step 108. The nonmagnetic seed layer substantially covering at least the bottom and sides of the trench. The nonmagnetic seed layer may have a thickness of at least three hundred Angstroms and not more than seven hundred Angstroms. In a preferred embodiment, the nonmagnetic seed layer has a thickness of at least four hundred Angstroms and not more than six hundred Angstroms. In some embodiments, the nonmagnetic seed layer may act as a stop layer for a planarization process, such as a chemical mechanical planarization (CMP). In such embodiments, the nonmagnetic seed layer may include at least one of Ru and Ta. However, the nonmagnetic seed layer might include other and/or different materials. In other embodiments, the nonmagnetic seed layer may not act as a stop layer for a planarization process. In such embodiments, the nonmagnetic seed layer might include at least one of NiNb, NiCr, Ti, Cr, and Au. However, the nonmagnetic seed layer might include other and/or different materials.
A PMR material is plated on at least a portion of the seed layer, via step 110. The PMR material is magnetic and may include one or more materials. Moreover, the PMR material may include multiple layers. In addition, the PMR material fills the trench. A portion of the PMR pole material is removed, via step 112. Step 112 is preferably a planarization step, such as a CMP. Thus, a remaining portion of the PMR pole material, residing primarily in the trench, forms a PMR pole. The width of the PMR pole, as measured at the top of the PMR pole, has a width of at least 0.08 micron and not more than 0.17 micron.
The method 100 allows for formation of a PMR pole. Because the thickness of the insulator is known and the metallic underlayer resides at the bottom of the trench, the height of the trench is known. Consequently, the height of the PMR pole is known and variations in the height of the PMR pole may be reduced using the method 100. In addition, because of the use of the nonmagnetic seed layer, only the portion of the perpendicular magnetic pole material remaining after step 112 forms the PMR pole. Stated differently, because it is nonmagnetic, the seed layer is not part of the PMR pole. As a result, the trench formed in step 106 may be made wider without affecting the width of the PMR pole. The nonmagnetic seed layer is, therefore, better able to adhere to both the sides and bottom of the trench and form a continuous layer within the trench. The PMR pole material is better able to adhere to the seed layer and remain in the trench because the nonmagnetic seed layer may form a more continuous layer within the trench. Thus, the yield is improved using the method 100.
Referring to FIGS. 5 and 6A-6G, a metallic underlayer is formed, via step 122. The metallic may be formed on an underlying insulator. In such an embodiment, a shallow trench is may be formed in the insulating layer, and the metallic underlayer is formed in the trench. However, in another embodiment, the metallic underlayer may be part of another structure, such as a pole. The metallic underlayer may include nonmagnetic metallic materials. Examples of such materials include, but are not limited to Cr, NiCr, NiNb, Ru, and Ta. An insulator is provided on at least part of the metallic underlayer, via step 124. In one embodiment, the insulator substantially covers all of the metallic underlayer. In another embodiment, the insulator may cover only a portion of the metallic underlayer. In a preferred embodiment, the insulator is alumna. The steps 102 and 104 are analogous to the method 70 depicted in
A photoresist mask is provided on the metal mask layer 206, via step 128. In a preferred embodiment, the photoresist mask is a bilayer mask. However, in another embodiment, another number of layers may be used. For example, a single layer photoresist mask might be utilized.
The pattern of the photoresist mask 208 is transferred to the metal mask layer 206, via step 130. Thus, a metal mask is formed. Step 130 preferably includes performing an IBE or RIE to provide a pattern the metal mask. In a preferred embodiment, step 130 includes stripping the photoresist mask 208.
A trench is formed in the insulator 204, via step 132. In a preferred embodiment, step 132 is performed using a RIE.
A nonmagnetic seed layer is deposited, via step 134. The nonmagnetic seed layer may also act as a stop layer for a planarization, discussed below. In some embodiments, nonmagnetic seed layer includes at least one of Ru and Ta. Because the width of the trench 216 is sufficiently large, the nonmagnetic seed layer substantially covers at least the bottom and sides of the trench 216.
A PMR pole material is provided on at least a portion of the seed layer, via step 136. In a preferred embodiment, step 136 is performed by plating the PMR pole material. The PMR pole material is magnetic and may include one or more materials. Moreover, the PMR pole material may include multiple layers.
The PMR transducer 200 is planarized, via step 138. In the embodiment shown, the nonmagnetic seed layer 218 is a stop layer for the planarization performed in step 138. In addition, step 138 preferably includes performing a CMP to remove a portion of the perpendicular magnetic pole material. Thus, the nonmagnetic seed layer 218 is a CMP stop layer in the embodiment shown. Moreover, the metal mask 206″ may also act as a CMP stop layer for step 138. A remaining portion of the PMR pole material forms the PMR pole.
The method 120 thus allows for formation of a PMR pole. Because the thickness of the insulator 204 is known and the metallic underlayer 202 resides at the bottom of the trench 216, the height of the trench 216 is known. Consequently, the height of the PMR pole 220′ is known and variations in the height of the PMR pole 220′ may be reduced. In addition, because of the use of the nonmagnetic seed layer 218, only the portion of the PMR pole material 220 remaining after step 138 forms the PMR pole 220′. Stated differently, because it is nonmagnetic, the seed layer 218 is not part of the PMR pole 220′. As a result, the trench 216 may be made wider without affecting the width of the PMR pole 220′. The nonmagnetic seed layer 218 is, therefore, better able to adhere to both the sides and bottom of the trench 216 and form a continuous layer within the trench 216. The PMR pole material 220 is thus better able to adhere to the seed layer and remain in the trench 216. The yield may thereby be improved using the method 120. However, it may be noted that because the metal mask 206′ may be exposed to an RIE performed to form the trench 216 in step 132, the corners 207 of the metal mask 206″ may be rounded. Consequently, the nonmagnetic seed layer 218 and the PMR pole 220′ may have rounded corners that may adversely affect performance of the PMR pole 220′.
Referring to FIGS. 7 and 8A-8G, a metallic underlayer is formed, via step 152. The metallic may be formed on an underlying insulator. In such an embodiment, a shallow trench is may be formed in the insulating layer, and the metallic underlayer is formed in the trench. However, in another embodiment, the metallic underlayer may be part of another structure, such as a pole. The metallic underlayer may include nonmagnetic metallic materials. Examples of such materials include, but are not limited to Cr, NiCr, NiNb, Ru, and Ta. An insulator is provided on at least part of the metallic underlayer, via step 154. In one embodiment, the insulator substantially covers all of the metallic underlayer. In another embodiment, the insulator may cover only a portion of the metallic underlayer. In a preferred embodiment, the insulator is alumna. The steps 102 and 104 are analogous to the method 70 depicted in
A photoresist mask is provided on the metal mask layer 258, via step 160. In a preferred embodiment, the photoresist mask is a bilayer mask. In another embodiment, the photoresist mask may have another number of layers. For example, the photoresist mask may be a single layer mask.
The pattern of the photoresist mask 260 is transferred to the metal mask layer 258 and the planarization stop layer 256, via step 162. Thus, a metal mask and an aperture in the underlying planarization stop layer are formed. Step 162 preferably includes performing an IBE to provide a pattern the metal mask 258 and the aperture in the planarization stop layer 256. In a preferred embodiment, step 162 also includes stripping the photoresist mask 260.
A trench is formed in the insulator 254, via step 164. In a preferred embodiment, step 164 is performed using a RIE.
A nonmagnetic seed layer is deposited, via step 166. The nonmagnetic seed layer deposited in step 166 is preferably not a stop layer for the planarization described below. In some embodiments, nonmagnetic seed layer includes at least one of NiNb, NiCr, Ti, Cr, and Au. Because the width of the trench 266 is sufficiently large, the nonmagnetic seed layer substantially covers at least the bottom and sides of the trench 266.
A PMR pole material is provided on at least a portion of the nonmagnetic seed layer 268, via step 168. In a preferred embodiment, step 168 is performed by plating the PMR pole material. The PMR pole material is magnetic and may include one or more materials. Moreover, the PMR pole material may include multiple layers.
The PMR transducer 250 is planarized, via step 170. In the embodiment shown, the nonmagnetic seed layer 268 outside of the trench 266 and above the stop layer 256′ as well as the metal mask 258′ are removed in the planarization performed in step 170. In addition, step 170 preferably includes performing a CMP to remove a portion of the perpendicular magnetic pole material 270. Thus, a remaining portion of the PMR pole material 270 forms the PMR pole.
The method 150 thus allows for formation of a PMR pole. Because the thickness of the insulator 254 is known and the metallic underlayer 252 resides at the bottom of the trench 266, the height of the trench 266 is known. Consequently, the height of the PMR pole 270′ is known and variations in the height of the PMR pole 270′ may be reduced. In addition, because of the use of the nonmagnetic seed layer 268, only the portion of the PMR pole material 270 remaining after step 170 forms the PMR pole 270′. Stated differently, because it is nonmagnetic, the seed layer 268 is not part of the PMR pole 270′. As a result, the trench 266 may be made wider without affecting the width of the PMR pole 270′. The nonmagnetic seed layer 268 is, therefore, better able to adhere to both the sides and bottom of the trench 266 and form a continuous layer within the trench 266. The PMR pole material 270 is thus better able to adhere to the seed layer and remain in the trench 266. The yield may thereby be improved using the method 150. In addition, it may be noted that despite the possibility of the metal mask 258′ being exposed to an RIE performed to form the trench 266 in step 164, any rounding in the corners 257 of the metal mask do not affect the PMR pole 270′. The metal mask 258′ and the portion of the PMR pole material 270 at the same height as the metal mask 258′ are removed during the planarization performed in step 170. Consequently, the PMR pole 270′ does not have rounded corners that may otherwise adversely affect performance of the PMR pole 270′.
Thus, using the methods 100, 120, and 150, fabrication, performance, and reliability of PMR transducers 200 and 250 may be improved.
Patent | Priority | Assignee | Title |
10037770, | Nov 12 2015 | Western Digital Technologies, INC | Method for providing a magnetic recording write apparatus having a seamless pole |
10074387, | Dec 21 2014 | Western Digital Technologies, INC | Method and system for providing a read transducer having symmetric antiferromagnetically coupled shields |
10115419, | Mar 24 2015 | Western Digital Technologies, INC | Method for AFC shields for multiple sensor magnetic transducers and magnetic transducers having multiple sensors and AFC shields |
10121495, | Nov 30 2015 | Western Digital Technologies, INC | Magnetic recording write apparatus having a stepped conformal trailing shield |
10242700, | Jun 26 2015 | Western Digital Technologies, INC | Magnetic reader having a nonmagnetic insertion layer for the pinning layer |
10381029, | Nov 10 2015 | Western Digital Technologies, INC | Method and system for providing a HAMR writer including a multi-mode interference device |
10490500, | Jul 18 2014 | Taiwan Semiconductor Manufacturing Company, Ltd. | Metal line structure and method |
10553241, | Dec 17 2014 | Western Digital Technologies, INC | Near-field transducer (NFT) for a heat assisted magnetic recording (HAMR) device |
11101216, | Jul 18 2014 | Taiwan Semiconductor Manufacturing Company, Ltd. | Metal line structure and method |
8257597, | Mar 03 2010 | Western Digital Technologies, INC | Double rie damascene process for nose length control |
8468682, | Jun 09 2006 | Western Digital Technologies, INC | Method for manufacturing perpendicular magnetic recording transducers |
8705205, | Jun 27 2011 | Western Digital Technologies, INC | Magnetic recording head having a dual sidewall angle |
8792208, | May 25 2012 | Western Digital Technologies, INC | Method for providing side shields having non-conformal regions for a magnetic recording transducer |
8830628, | Feb 23 2009 | Western Digital Technologies, INC | Method and system for providing a perpendicular magnetic recording head |
8861134, | Jun 09 2006 | Western Digital Technologies, INC | Method and system for providing perpendicular magnetic recording transducers utilizing a damascene approach |
8879207, | Dec 20 2011 | Western Digital Technologies, INC | Method for providing a side shield for a magnetic recording transducer using an air bridge |
8883017, | Mar 12 2013 | Western Digital Technologies, INC | Method and system for providing a read transducer having seamless interfaces |
8917581, | Dec 18 2013 | Western Digital Technologies, INC | Self-anneal process for a near field transducer and chimney in a hard disk drive assembly |
8923102, | Jul 16 2013 | Western Digital Technologies, INC | Optical grating coupling for interferometric waveguides in heat assisted magnetic recording heads |
8947985, | Jul 16 2013 | Western Digital Technologies, INC | Heat assisted magnetic recording transducers having a recessed pole |
8953422, | Jun 10 2014 | Western Digital Technologies, INC | Near field transducer using dielectric waveguide core with fine ridge feature |
8958272, | Jun 10 2014 | Western Digital Technologies, INC | Interfering near field transducer for energy assisted magnetic recording |
8970988, | Dec 31 2013 | Western Digital Technologies, INC | Electric gaps and method for making electric gaps for multiple sensor arrays |
8971160, | Dec 19 2013 | Western Digital Technologies, INC | Near field transducer with high refractive index pin for heat assisted magnetic recording |
8976635, | Jun 10 2014 | Western Digital Technologies, INC | Near field transducer driven by a transverse electric waveguide for energy assisted magnetic recording |
8980109, | Dec 11 2012 | Western Digital Technologies, INC | Method for providing a magnetic recording transducer using a combined main pole and side shield CMP for a wraparound shield scheme |
8982508, | Oct 31 2011 | Western Digital Technologies, INC | Method for providing a side shield for a magnetic recording transducer |
8984740, | Nov 30 2012 | Western Digital Technologies, INC | Process for providing a magnetic recording transducer having a smooth magnetic seed layer |
8988812, | Nov 27 2013 | Western Digital Technologies, INC | Multi-sensor array configuration for a two-dimensional magnetic recording (TDMR) operation |
8988825, | Feb 28 2014 | Western Digital Technologies, INC | Method for fabricating a magnetic writer having half-side shields |
8993217, | Apr 04 2013 | Western Digital Technologies, INC | Double exposure technique for high resolution disk imaging |
8995087, | Nov 29 2006 | Western Digital Technologies, INC | Perpendicular magnetic recording write head having a wrap around shield |
8997832, | Nov 23 2010 | Western Digital Technologies, INC | Method of fabricating micrometer scale components |
9001467, | Mar 05 2014 | Western Digital Technologies, INC | Method for fabricating side shields in a magnetic writer |
9001628, | Dec 16 2013 | Western Digital Technologies, INC | Assistant waveguides for evaluating main waveguide coupling efficiency and diode laser alignment tolerances for hard disk |
9007719, | Oct 23 2013 | Western Digital Technologies, INC | Systems and methods for using double mask techniques to achieve very small features |
9007725, | Oct 07 2014 | Western Digital Technologies, INC | Sensor with positive coupling between dual ferromagnetic free layer laminates |
9007879, | Jun 10 2014 | Western Digital Technologies, INC | Interfering near field transducer having a wide metal bar feature for energy assisted magnetic recording |
9013836, | Apr 02 2013 | Western Digital Technologies, INC | Method and system for providing an antiferromagnetically coupled return pole |
9042051, | Aug 15 2013 | Western Digital Technologies, INC | Gradient write gap for perpendicular magnetic recording writer |
9042052, | Jun 23 2014 | Western Digital Technologies, INC | Magnetic writer having a partially shunted coil |
9042057, | Jan 09 2013 | Western Digital Technologies, INC | Methods for providing magnetic storage elements with high magneto-resistance using Heusler alloys |
9042058, | Oct 17 2013 | Western Digital Technologies, INC | Shield designed for middle shields in a multiple sensor array |
9042208, | Mar 11 2013 | Western Digital Technologies, INC | Disk drive measuring fly height by applying a bias voltage to an electrically insulated write component of a head |
9053735, | Jun 20 2014 | Western Digital Technologies, INC | Method for fabricating a magnetic writer using a full-film metal planarization |
9064507, | Jul 31 2009 | Western Digital Technologies, INC | Magnetic etch-stop layer for magnetoresistive read heads |
9064527, | Apr 12 2013 | Western Digital Technologies, INC | High order tapered waveguide for use in a heat assisted magnetic recording head |
9064528, | May 17 2013 | Western Digital Technologies, INC | Interferometric waveguide usable in shingled heat assisted magnetic recording in the absence of a near-field transducer |
9065043, | Jun 29 2012 | Western Digital Technologies, INC | Tunnel magnetoresistance read head with narrow shield-to-shield spacing |
9070381, | Apr 12 2013 | Western Digital Technologies, INC | Magnetic recording read transducer having a laminated free layer |
9082423, | Dec 18 2013 | Western Digital Technologies, INC | Magnetic recording write transducer having an improved trailing surface profile |
9087527, | Oct 28 2014 | Western Digital Technologies, INC | Apparatus and method for middle shield connection in magnetic recording transducers |
9087534, | Dec 20 2011 | Western Digital Technologies, INC | Method and system for providing a read transducer having soft and hard magnetic bias structures |
9093639, | Feb 21 2012 | Western Digital Technologies, INC | Methods for manufacturing a magnetoresistive structure utilizing heating and cooling |
9104107, | Apr 03 2013 | Western Digital Technologies, INC | DUV photoresist process |
9111550, | Dec 04 2014 | Western Digital Technologies, INC | Write transducer having a magnetic buffer layer spaced between a side shield and a write pole by non-magnetic layers |
9111558, | Mar 14 2014 | Western Digital Technologies, INC | System and method of diffractive focusing of light in a waveguide |
9111564, | Apr 02 2013 | Western Digital Technologies, INC | Magnetic recording writer having a main pole with multiple flare angles |
9123358, | Jun 11 2012 | Western Digital Technologies, INC | Conformal high moment side shield seed layer for perpendicular magnetic recording writer |
9123359, | Dec 22 2010 | Western Digital Technologies, INC | Magnetic recording transducer with sputtered antiferromagnetic coupling trilayer between plated ferromagnetic shields and method of fabrication |
9123362, | Mar 22 2011 | Western Digital Technologies, INC | Methods for assembling an electrically assisted magnetic recording (EAMR) head |
9123374, | Feb 12 2015 | Western Digital Technologies, INC | Heat assisted magnetic recording writer having an integrated polarization rotation plate |
9135930, | Mar 06 2014 | Western Digital Technologies, INC | Method for fabricating a magnetic write pole using vacuum deposition |
9135937, | May 09 2014 | Western Digital Technologies, INC | Current modulation on laser diode for energy assisted magnetic recording transducer |
9142233, | Feb 28 2014 | Western Digital Technologies, INC | Heat assisted magnetic recording writer having a recessed pole |
9147404, | Mar 31 2015 | Western Digital Technologies, INC | Method and system for providing a read transducer having a dual free layer |
9147408, | Dec 19 2013 | Western Digital Technologies, INC | Heated AFM layer deposition and cooling process for TMR magnetic recording sensor with high pinning field |
9153255, | Mar 05 2014 | Western Digital Technologies, INC | Method for fabricating a magnetic writer having an asymmetric gap and shields |
9159345, | Nov 23 2010 | Western Digital Technologies, INC | Micrometer scale components |
9159346, | Jun 10 2014 | Western Digital Technologies, INC | Near field transducer using dielectric waveguide core with fine ridge feature |
9183854, | Feb 24 2014 | Western Digital Technologies, INC | Method to make interferometric taper waveguide for HAMR light delivery |
9190079, | Sep 22 2014 | Western Digital Technologies, INC | Magnetic write pole having engineered radius of curvature and chisel angle profiles |
9190085, | Mar 12 2014 | Western Digital Technologies, INC | Waveguide with reflective grating for localized energy intensity |
9194692, | Dec 06 2013 | Western Digital Technologies, INC | Systems and methods for using white light interferometry to measure undercut of a bi-layer structure |
9202480, | Oct 14 2009 | Western Digital Technologies, INC | Double patterning hard mask for damascene perpendicular magnetic recording (PMR) writer |
9202493, | Feb 28 2014 | Western Digital Technologies, INC | Method of making an ultra-sharp tip mode converter for a HAMR head |
9213322, | Aug 16 2012 | Western Digital Technologies, INC | Methods for providing run to run process control using a dynamic tuner |
9214165, | Dec 18 2014 | Western Digital Technologies, INC | Magnetic writer having a gradient in saturation magnetization of the shields |
9214169, | Jun 20 2014 | Western Digital Technologies, INC | Magnetic recording read transducer having a laminated free layer |
9214172, | Oct 23 2013 | Western Digital Technologies, INC | Method of manufacturing a magnetic read head |
9230565, | Jun 24 2014 | Western Digital Technologies, INC | Magnetic shield for magnetic recording head |
9236560, | Dec 08 2014 | Western Digital Technologies, INC | Spin transfer torque tunneling magnetoresistive device having a laminated free layer with perpendicular magnetic anisotropy |
9245543, | Jun 25 2010 | Western Digital Technologies, INC | Method for providing an energy assisted magnetic recording head having a laser integrally mounted to the slider |
9245545, | Apr 12 2013 | Western Digital Technologies, INC | Short yoke length coils for magnetic heads in disk drives |
9245562, | Mar 30 2015 | Western Digital Technologies, INC | Magnetic recording writer with a composite main pole |
9251813, | Apr 19 2009 | Western Digital Technologies, INC | Method of making a magnetic recording head |
9263067, | May 29 2013 | Western Digital Technologies, INC | Process for making PMR writer with constant side wall angle |
9263071, | Mar 31 2015 | Western Digital Technologies, INC | Flat NFT for heat assisted magnetic recording |
9269382, | Jun 29 2012 | Western Digital Technologies, INC | Method and system for providing a read transducer having improved pinning of the pinned layer at higher recording densities |
9275657, | Aug 14 2013 | Western Digital Technologies, INC | Process for making PMR writer with non-conformal side gaps |
9280990, | Dec 11 2013 | Western Digital Technologies, INC | Method for fabricating a magnetic writer using multiple etches |
9286919, | Dec 17 2014 | Western Digital Technologies, INC | Magnetic writer having a dual side gap |
9287494, | Jun 28 2013 | Western Digital Technologies, INC | Magnetic tunnel junction (MTJ) with a magnesium oxide tunnel barrier |
9305583, | Feb 18 2014 | Western Digital Technologies, INC | Method for fabricating a magnetic writer using multiple etches of damascene materials |
9311952, | Jun 10 2014 | Western Digital Technologies, INC | Interfering near field transducer for energy assisted magnetic recording |
9312064, | Mar 02 2015 | Western Digital Technologies, INC | Method to fabricate a magnetic head including ion milling of read gap using dual layer hard mask |
9318130, | Jul 02 2013 | Western Digital Technologies, INC | Method to fabricate tunneling magnetic recording heads with extended pinned layer |
9336814, | Mar 12 2013 | Western Digital Technologies, INC | Inverse tapered waveguide for use in a heat assisted magnetic recording head |
9343086, | Sep 11 2013 | Western Digital Technologies, INC | Magnetic recording write transducer having an improved sidewall angle profile |
9343087, | Dec 21 2014 | Western Digital Technologies, INC | Method for fabricating a magnetic writer having half shields |
9343098, | Aug 23 2013 | Western Digital Technologies, INC | Method for providing a heat assisted magnetic recording transducer having protective pads |
9349392, | May 24 2012 | Western Digital Technologies, INC | Methods for improving adhesion on dielectric substrates |
9349393, | Mar 05 2014 | Western Digital Technologies, INC | Magnetic writer having an asymmetric gap and shields |
9349394, | Oct 18 2013 | Western Digital Technologies, INC | Method for fabricating a magnetic writer having a gradient side gap |
9361913, | Jun 03 2013 | Western Digital Technologies, INC | Recording read heads with a multi-layer AFM layer methods and apparatuses |
9361914, | Jun 18 2014 | Western Digital Technologies, INC | Magnetic sensor with thin capping layer |
9368134, | Dec 16 2010 | Western Digital Technologies, INC | Method and system for providing an antiferromagnetically coupled writer |
9384763, | Mar 26 2015 | Western Digital Technologies, INC | Dual free layer magnetic reader having a rear bias structure including a soft bias layer |
9384765, | Sep 24 2015 | Western Digital Technologies, INC | Method and system for providing a HAMR writer having improved optical efficiency |
9396742, | Nov 30 2012 | Western Digital Technologies, INC | Magnetoresistive sensor for a magnetic storage system read head, and fabrication method thereof |
9396743, | Feb 28 2014 | Western Digital Technologies, INC | Systems and methods for controlling soft bias thickness for tunnel magnetoresistance readers |
9406331, | Jun 17 2013 | Western Digital Technologies, INC | Method for making ultra-narrow read sensor and read transducer device resulting therefrom |
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Patent | Priority | Assignee | Title |
4274022, | Jun 16 1978 | Siemens Aktiengesellschaft | Evacuating device for generating an insulating vacuum around the superconducting winding of a rotor |
4404609, | Oct 30 1981 | International Business Machines Corporation | Thin film inductive transducer for perpendicular recording |
4546398, | Jul 03 1981 | Fujitsu Limited | Perpendicular magnetic recording and reproducing head |
4636897, | Oct 15 1982 | Hitachi, Ltd. | Perpendicular magnetic recording and reproducing thin film head |
4646429, | Oct 20 1982 | Fuji Photo Film Co., Ltd. | Method of making magnetic head |
4779463, | Jan 13 1987 | BEI SENSORS & SYSTEMS COMPANY, INC , A CORP OF DELAWARE | Servo accelerometer |
4855854, | Feb 09 1987 | Sumitomo Metal Industries, Ltd | Thin-film magnetic head |
4943882, | Feb 09 1987 | Thin-film, perpendicular magnetic recording and reproducing head | |
5027247, | Oct 29 1987 | FUJIFILM Corporation | Film magnetic head for high frequency recording |
5181151, | Apr 19 1990 | SUMITOMO SPECIAL METALS CO , LTD ; Denki Kagaku Kogyo Kabushiki Kaisha | Thin-film perpendicular magnetic recording and reproducing head having thin magnetic shield film on side surfaces |
5225953, | Nov 09 1989 | Sumitomo Metal Industries, Ltd | Magnetic thin film head of a single magnetic pole for perpendicular recording and reproduction |
5393233, | Jul 14 1993 | United Microelectronics Corporation | Process for fabricating double poly high density buried bit line mask ROM |
5578857, | Jul 14 1993 | United Microelectronics Corporation | Double poly high density buried bit line mask ROM |
6063711, | Apr 28 1998 | Taiwan Semiconductor Manufacturing Company | High selectivity etching stop layer for damascene process |
6072672, | May 06 1997 | MARIANA HDD B V ; HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B V | Write head with notched P1 and minimum overmilled P1 and P2 |
6211090, | Mar 21 2000 | Everspin Technologies, Inc | Method of fabricating flux concentrating layer for use with magnetoresistive random access memories |
6261918, | Oct 04 1999 | Newport Fab, LLC | Method for creating and preserving alignment marks for aligning mask layers in integrated circuit manufacture |
6292329, | Oct 02 1997 | Sony Corporation | Thin film single magnetic head |
6315839, | Oct 21 1998 | International Business Machines Corporation | Method of making a keeper layer for a spin valve sensor with low intrinsic anisotropy field |
6353995, | Dec 11 1998 | TDK Corporation | Thin film mangetic head and method of manufacturing same |
6391757, | Jun 06 2001 | United Microelectronics Corp. | Dual damascene process |
6433970, | Jun 07 1999 | Western Digital Technologies, INC | Structure and method for redeposition free thin film CPP read sensor fabrication |
6475062, | Dec 28 1998 | TDK Corporation | Film thickness measuring method, polishing method, fabrication method of thin film magnetic head and substrate for forming the thin film magnetic head |
6501619, | Apr 27 2000 | SAMSUNG ELECTRONICS CO , LTD | Inductive magnetic recording head having inclined magnetic read/write pole and method of making same |
6504675, | Jan 12 2000 | Seagate Technology LLC | Perpendicular magnetic recording heads with write pole shaped to reduce skew effects during writing |
6513228, | Jan 05 2000 | Seagate Technology LLC | Method for forming a perpendicular recording read/write head |
6522007, | Jun 15 2001 | Mitsubishi Denki Kabushiki Kaisha | Semiconductor device having dummy patterns for metal CMP |
6564445, | Mar 29 1999 | Kabushiki Kaisha Toshiba | Magnetic head manufacturing method |
6587314, | May 16 2000 | GOOGLE LLC | Enhanced silicon and ceramic magnetoresistive read/write head and a method for producing the same |
6709322, | Mar 29 2001 | Applied Materials, Inc | Apparatus for aligning a surface of an active retainer ring with a wafer surface for chemical mechanical polishing |
6740471, | Mar 20 2002 | Taiwan Semiconductor Manufacturing Company | Photoresist adhesion improvement on metal layer after photoresist rework by extra N2O treatment |
6743642, | Nov 06 2002 | Infineon Technologies AG | Bilayer CMP process to improve surface roughness of magnetic stack in MRAM technology |
6751054, | Jul 13 2000 | TDK Corporation | Thin-film magnetic head for perpendicular magnetic recording having main magnetic pole layer on flat surface |
6757141, | Jan 18 2002 | HGST NETHERLANDS B V | Perpendicular recording write head with a ferromagnetic shaping layer |
6795277, | Jun 29 2001 | Hitachi Global Storage Technologies Japan, Ltd | Magnetic head and magnetic disk drive |
6807027, | Apr 03 2002 | Seagate Technology LLC | Ruthenium as non-magnetic seedlayer for electrodeposition |
6808442, | Dec 20 2001 | Applied Materials, Inc | Apparatus for removal/remaining thickness profile manipulation |
6809899, | Aug 20 2001 | Western Digital Technologies, INC | Magnetic heads for perpendicular recording with trapezoidal pole tips |
6833979, | Jun 07 1999 | Western Digital Technologies, INC | Structure and method for redeposition free thin film CPP read sensor fabrication |
6836957, | Dec 26 2000 | TDK Corporation | Method for making perpendicular magnetic recording head having inverted trapezoidal main magnetic pole layer |
6843707, | Mar 29 2001 | Lam Research Corporation | Methods for aligning a surface of an active retainer ring with a wafer surface for chemical mechanical polishing |
6876518, | Jan 05 2000 | Seagate Technology LLC | Perpendicular magnetic recording head |
6876519, | Sep 20 1999 | Seagate Technology, LLC; Seagate Technology LLC | Magnetic recording head including background magnetic field generator |
6952867, | Dec 26 2000 | TDK Corporation | Method for manufacturing perpendicular magnetic recording head having inverted trapezoidal main magnetic pole layer |
6960281, | Mar 21 2003 | Headway Technologies, Inc. | Method to make a wider trailing pole structure by self-aligned pole trim process |
6962771, | Oct 13 2000 | Taiwan Semiconductor Manufacturing Company, Ltd. | Dual damascene process |
7024756, | Jul 30 2003 | Hitachi Global Storage Technologies Netherlands, B.V. | Method of making a perpendicular recording magnetic head pole tip with an etchable adhesion CMP stop layer |
7029376, | Feb 28 2005 | Hitachi Global Storage Technologies Netherlands B.V. | Process of fabricating write pole in magnetic recording head using rhodium CMP stop layer |
7206166, | Aug 29 2002 | TDK Corporation | Thin film magnetic head and method of manufacturing the same |
7227720, | Jun 21 2004 | Headway Technologies, Inc | Magnetic head for perpendicular magnetic recording and method of manufacturing same |
7248434, | Mar 10 2004 | Hitachi Global Storage Technologies Netherlands B.V. | Planarized perpendicular pole tip system and method for manufacturing the same |
7288487, | Dec 01 2004 | Advanced Micro Devices, INC | Metal/oxide etch after polish to prevent bridging between adjacent features of a semiconductor structure |
7296339, | Sep 08 2004 | Western Digital Technologies, INC | Method for manufacturing a perpendicular magnetic recording head |
7370405, | Jul 24 2001 | Hitachi Global Storage Technologies Japan, Ltd. | Fabrication method of a high gradient-field recording head for perpendicular magnetic recording |
7508627, | Mar 03 2006 | Western Digital Technologies, INC | Method and system for providing perpendicular magnetic recording transducers |
7518824, | Mar 07 2005 | Headway Technologies, Inc | Magnetic head for perpendicular magnetic recording that has a pole layer having a shape for easy forming, reducing track width and improved writing characteristics |
7552523, | Jul 01 2005 | Western Digital (Fremont), LLC | Method for manufacturing a perpendicular magnetic recording transducer |
7911735, | Mar 09 2007 | Western Digital Technologies, INC | Perpendicular magnetic recording head utilizing a nonmagnetic underlayer layer |
20010008501, | |||
20010035357, | |||
20020006013, | |||
20020012195, | |||
20020012196, | |||
20020151254, | |||
20020190382, | |||
20020191336, | |||
20022100336, | |||
20030039064, | |||
20030071263, | |||
20030117749, | |||
20030203510, | |||
20040001283, | |||
20040008446, | |||
20040008451, | |||
20040032692, | |||
20040075927, | |||
20040102138, | |||
20040150912, | |||
20040161576, | |||
20040252415, | |||
20040257711, | |||
20050011064, | |||
20050024779, | |||
20050068671, | |||
20060044681, | |||
20060109588, | |||
20060139802, | |||
20060168603, | |||
20080080233, | |||
20080148301, | |||
20080184278, | |||
20080278861, | |||
20080297945, | |||
20080316644, | |||
20100078406, | |||
20100113486, |
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